Admittedly tested with only leap 15.0 and recent Tumbleweed VM's, but libvirt
fails to run any of my existing virutal machines or create new virtual
machines, failing each time with the following error (shown on the virt-manager
console):

Error starting domain: internal error: process exited while connecting to
monitor: 2018-05-31T15:58:05.465552Z qemu-system-x86_64: -device
ccid-card-passthru,chardev=charsmartcard0,id=smartcard0,bus=ccid0.0:
ccid-card-passthru: initing chardev

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 89, in
cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 125, in tmpcb
    callback(*args, **kwargs)
  File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 82, in
newfn
    ret = fn(self, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/domain.py", line 1508, in startup
    self._backend.create()
  File "/usr/lib64/python3.6/site-packages/libvirt.py", line 1069, in create
    if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self)
libvirt.libvirtError: internal error: process exited while connecting to
monitor: 2018-05-31T15:58:05.465552Z qemu-system-x86_64: -device
ccid-card-passthru,chardev=charsmartcard0,id=smartcard0,bus=ccid0.0:
ccid-card-passthru: initing chardev